From: Corentin Labbe <clabbe@xxxxxxxxxxxx> [ Upstream commit 014dfa26ce1c647af09bf506285ef67e0e3f0a6b ] MTU cannot be changed on dwmac-sun8i. (ip link set eth0 mtu xxx returning EINVAL) This is due to tx_fifo_size being 0, since this value is used to compute valid MTU range. Like dwmac-sunxi (with commit 806fd188ce2a ("net: stmmac: dwmac-sunxi: Provide TX and RX fifo sizes")) dwmac-sun8i need to have tx and rx fifo sizes set. I have used values from datasheets. After this patch, setting a non-default MTU (like 1000) value works and network is still useable. Tested-on: sun8i-h3-orangepi-pc Tested-on: sun8i-r40-bananapi-m2-ultra Tested-on: sun50i-a64-bananapi-m64 Tested-on: sun50i-h5-nanopi-neo-plus2 Tested-on: sun50i-h6-pine-h64 Fixes: 9f93ac8d408 ("net-next: stmmac: Add dwmac-sun8i") Reported-by: Belisko Marek <marek.belisko@xxxxxxxxx> Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c index c4c9cbdeb601..2f6258ca9515 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c @@ -1206,6 +1206,8 @@ static int sun8i_dwmac_probe(struct platform_device *pdev) plat_dat->init = sun8i_dwmac_init; plat_dat->exit = sun8i_dwmac_exit; plat_dat->setup = sun8i_dwmac_setup; + plat_dat->tx_fifo_size = 4096; + plat_dat->rx_fifo_size = 16384; ret = sun8i_dwmac_init(pdev, plat_dat->bsp_priv); if (ret) -- 2.30.1